Yuuji Abe meets a mysterious girl at the subway station. This chance encounter with Kana and Rou, her wolf companion entangles Yuuji in a plot concocted by the Seven Heads, a group of half-demons who want to bring a type of utopia where humans and demons can live together peacefully, albeit through unscrupulous and forceful means. As the group targets Kana and her companions, Yuujo begins to discover the truth not only about Kana, but about his own ancestors, and ultimately comes to terms with his budding feelings for this mysterious girl.